That is because Californian state law allows sales of Medical Marijuana, and they can't prove that the sales were illegal and that there were problematic things included because it's legal in the state.
I believe the answer is: because there is nothing “illegal” going on
According to the law, the selling of marijuana is legal if it purchased for medicinal purpose. ( to alleviate pain, headache, help go through cancer, etc)
The harbormaster health center was accused to sel marijuana for recreational purposes, but the DEA has no way to proof this.
